Rigging assembly for a dragline excavator

ABSTRACT

A rigging assembly for a dragline excavator where the rigging assembly has a first upper hoist link and a second upper hoist link. The rigging assembly also has an equalization member extending between the first upper hoist link and the second upper hoist link. The equalization member is formed from a flexible material.

FIELD OF THE INVENTION

The invention relates to a rigging assembly for a dragline excavator. In particular, although not exclusively, the invention relates to an improved upper hoist rigging assembly for a dragline excavator.

BACKGROUND TO THE INVENTION

Dragline excavators are commonly employed on mine sites for tasks to strip overburden to expose coal seams. Draglines have been in use for approximately 100 years in this capacity. However, machine sizes, bucket styles and sizes, and rigging arrangements have evolved as technology has advanced.

Draglines have a high capital cost and significant ongoing maintenance costs and hence represent a substantial investment for the mine operator. Consequently, it is essential that the dragline has a high availability and demonstrates efficiency of operation to ensure that the mine operator realizes an optimal return on investment.

In order to optimise the productivity of a dragline it is desirable to minimize the time between each dig cycle, minimize maintenance cost of the dragline rigging and provide dragline rigging for optimum excavation capabilities.

The design of the dragline bucket has evolved to provide a bucket that fills more quickly and efficiently than more traditional buckets. For example, Australian Patent Application 2002301250 provides for a dragline bucket design that has a relatively low drag energy requirement during the fill portion of the dig cycle and thus reducing the required fill time than that previously observed whilst also increasing the payload.

However, whilst bucket design has evolved, the rigging that controls the motion of the bucket has remained largely unchanged. The interplay between the dragline bucket and the rigging is an important factor in ensuring the dragline reaches optimal production.

OBJECT OF THE INVENTION

It is an object of the invention to overcome or at least alleviate one or more of the above problems and/or provide the consumer with a useful or commercial choice.

DISCLOSURE OF THE INVENTION

In one form, although it need not be the only or indeed the broadest form, the invention resides in a rigging assembly for a dragline excavator, the rigging assembly comprising:

a first upper hoist link;

a second upper hoist link; and

an equalization member extending between the first upper hoist link and the second upper hoist link;

wherein, the equalization member is formed from a flexible material.

Preferably, the equalization member is in the form of a link chain.

Suitably, the equalization member is rotatably secured at an end thereof to the first upper hoist link and is rotatably secured at an opposing end thereof to the second upper hoist link.

Optionally, the equalization member is rotatably secured at either end thereof to a clevis arm of a respective upper hoist link by way of a pin.

Suitably, a link of an upper hoist chain is secured to each clevis arm of the upper hoist links by way of the retaining pin.

Preferably, a dump block is secured to each upper hoist link.

In a further form, the invention resides in a rigging assembly for a dragline excavator, the rigging assembly comprising:

a first upper hoist link;

a second upper hoist link; and

an equalization member extending between the first upper hoist link and the second upper hoist link, the equalization member being secured at an end thereof to the first upper hoist link by way of a retainer and being secured at an opposed end thereof to the second upper hoist link by way of a retainer;

an upper hoist chain secured to the first upper hoist link by way of the respective retainer; and

an upper hoist chain secured to the second upper hoist link by way of the respective retainer.

Preferably, the retainer is in the form of a retaining pin.

Further features of the present invention will become apparent from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

To assist in understanding the invention and to enable a person skilled in the art to put the invention into practical effect preferred embodiments of the invention will be described by way of example only with reference to the accompanying drawings, wherein:

FIG. 1A shows a perspective view of a prior art dragline excavator rigging assembly;

FIG. 1B shows a close up perspective view of the upper hoist rigging forming part of the dragline excavator rigging assembly shown in FIG. 1A;

FIG. 2A shows a perspective view of a further prior art dragline excavator rigging assembly;

FIG. 2B shows a close up perspective view of the upper hoist rigging assembly forming part of the dragline excavator rigging assembly shown in FIG. 2A;

FIG. 3A shows a front perspective view of an upper hoist rigging assembly according to an embodiment of the invention;

FIG. 3B shows a rear perspective view of the upper hoist rigging assembly shown in FIG. 3A;

FIG. 4A shows a front perspective view of an upper hoist rigging assembly according to a further embodiment of the invention;

FIG. 4B shows a rear perspective view of the upper hoist rigging assembly shown in FIG. 4A; and

FIG. 5 shows a front perspective view of an upper hoist rigging assembly according to a further embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1A shows a perspective view of a prior art dragline rigging assembly 1000 and FIG. 1B shows a close up perspective view of an upper hoist rigging assembly 1100 forming part of the prior art dragline rigging assembly 1000 shown in FIG. 1A. The upper hoist rigging assembly 1100 is adapted for use with a single dump block 1009 as will be discussed in further detail below.

Dragline rigging assembly 1000 is used to control movement of the dragline bucket 1002 and includes an upper hoist rigging assembly 1100 formed from two hoist sockets 1111, a rigid connection bar 1112 pivotally connected to a lower end of each hoist socket 1111 thereby coupling the hoist sockets 1111.

Upper hoist rigging assembly 1100 rigging assembly further comprises a hoist link 1113 pivotally connected to a central region of rigid connection bar 1112 and a hitch 1114 pivotally connected to a lower end of hoist link 1113. Hitch 1114 has a pair of opposed clevis arms 1114A and a forwardly extending clevis arm 11146.

A hoist rope 1001 extend from an upper extent of each hoist socket 1111 in order to suspend the rigging assembly 1000 and bucket 1002 from a boom of the dragline (not shown). Furthermore, an upper hoist chain 1003A extend from each opposed clevis arm 1114A as shown with each upper hoist chain 1003A terminating at a respective end of spreader bar 1004. A lower hoist chain 1003B extends from each end of spreader bar 1004 and terminates at a respective trunion 1002A of dragline bucket 1002 as shown.

A drag chain 1005 extends from each opposed wing 1002B of dragline bucket 1002 with each drag chain terminating at a respective drag link 1006. The drag links 1006 are operatively connected by way of dump rigging assembly 1007.

Dump block 1009 is operatively, connected to forwardly extending clevis arm 114B of hitch 1114 of upper hoist assembly 1100. Dump rope 1008 extends from dump rigging assembly 1007 about dump block 1009 and terminates at arch 1002C of drag line bucket 1002.

FIG. 1A shows a perspective view of a prior art dragline rigging assembly 1000 and FIG. 1B shows a close up perspective view of an upper hoist rigging assembly 1100 forming part of the prior art dragline rigging assembly 1000 shown in FIG. 1A. The upper hoist rigging assembly 1100 is adapted for use with a single dump block 1009 as will be discussed in further detail below.

FIG. 2A shows a perspective view of a further prior art dragline rigging assembly 2000 and FIG. 2B shows a close up perspective view of an upper hoist rigging assembly 2100 forming part of the prior art dragline rigging assembly 2000 shown in FIG. 2A.

The dragline rigging assembly 2000 differs from that previously discussed in that the rigging assembly 2000 includes two dump blocks 2009 as will be discussed below.

As before, the rigging assembly 2000 includes an upper hoist rigging assembly 2100 formed from two hoist sockets 2111 and a rigid connection bar 2112. Rigid connection bar 2112 has a first pair of clevis arms 2112A extending from longitudinal ends of rigid connection bar 2112, a pair of forwardly extending clevis arms 2112B and a pair of upwardly extending clevis arms 2112C.

Each hoist socket 2111 is operably connected to a respective upwardly extending clevis arm 2112C of rigid connection bar 2112 by way of links 2120. Furthermore, each dump block 2009 is operably connected to a respective forwardly extending clevis arm 21126 of rigid connection bar 2112 by way of links 2120.

As the dragline rigging assembly 2000 has two dump blocks 2009, dump ropes 2008 extend from a respective drag link 2006, about a dump block 2009 and each terminates at arch 2002C

The dragline rigging assembly 2000 otherwise has features as previously discussed.

The prior art rigging assemblies discussed above include upper hoist rigging that comprises many components that add weight and complexity to the system.

FIG. 3A shows a front perspective view of an upper hoist rigging assembly 3000 according to an embodiment of the invention and FIG. 3B shows a rear perspective view of the upper hoist rigging assembly 3000.

Upper hoist rigging assembly 3000 comprises hoist sockets 3001 and a pair of upper hoist links 3002 each rotatably connected to a lower clevis arm 3001A of a respective hoist socket 3001.

Each upper hoist link 3002 has a lower clevis arm 3002A and a forwardly extending attachment portion 3002B.

A dump block 3009 is attached to the forwardly extending attachment portion 3002B of each upper hoist link 3002 by way of shackle 3020.

Furthermore, an upper hoist chain 3003A is attached to lower clevis arm 3002A of each upper hoist link 3002.

A flexible equalization member 3010 extends between the upper hoist links 3002. Flexible equalization member 3010 is secured to a respective upper hoist link 3002 by way of a retainer pin 3030 extending between lower clevis arms 3002A.

As shown, retainer pin 3030 secures both an end of flexible equalization member 3010 and shackle 3020 to lower clevis arm 3002A of each upper hoist link 3002. Alternatively, a separate retainer pin 303 may be used to secure an end of flexible equalization member 2010 to lower clevis arm 3002A and shackle 3020 to lower clevis arm 3002A.

In the embodiment, flexible equalization member 3010 is in the form of a link chain of similar construction to upper hoist chains 3003A.

FIG. 4A shows a front perspective view of an upper hoist rigging assembly 4000 according to a further embodiment of the invention and FIG. 4B shows a rear perspective view of the upper hoist rigging assembly 4000.

In the embodiment shown in FIG. 4A and FIG. 4B, the upper hoist rigging assembly 4000 includes a flexible equalization member 4010 formed from a light weight flexible material such as plastic coated wire rope, plastic coated textile ropes, plastic coated chain or the like.

Preferably, the flexible equalization member 4010 is of a unitary construction and has a shaft 4011 and clevis arms 4012 located at either end thereof. The flexible equalization member 4010 extends between the lower clevis arms 4002A of upper hoist links 4002. The flexible equalization member 4010 is secured at either end thereof to a respective upper hoist link 4002 by way of a retainer pin 4030 extending between each arm of the clevis arm 4002A. As described in previous embodiments, upper hoist chains 4003A are secured within clevis arms 4002A of each upper hoist link 4002 by way of the retainer pin 4030 such that a link of each upper hoist chain is secured within the clevis arms 4012 of flexible equalization member 4010.

Alternatively, separate pins 4030 may be used to secure the components within the clevis arms 4002A of each upper hoist link 4002.

In the embodiment a shackle 4040 is used to operatively secure each upper hoist chain 4003A to a lower clevis arm 4002A of a respective upper hoist link 4002.

In prior art rigging assemblies, there was no provision within the assembly for hoist rope equalization as the operative connection between the respective upper hoist links was a rigid connection. As such, by providing the flexible equalization member of the invention, better hoist rope equalization is achieved delivering improved hoist rope life.

Furthermore, by providing an upper hoist rigging assembly that has an upper hoist link with clevis arms adapted to secure both the flexible equalization member and an operative attachment to a respective upper hoist chain, the upper hoist rigging assembly of the invention has a lesser weight than prior art assemblies in view of the fact that less link members are required in the assembly. This reduced weight provides for power consumption advantages over prior art assemblies as a greater proportion of the dragline's energy output is devoted to moving payload in the dragline bucket rather than the hoist rigging assembly.

FIG. 5 shows a front perspective view of upper hoist rigging assembly 5000 according to a further embodiment of the invention. Upper hoist rigging assembly 5000 is adapted to attach to a single dumb block 5009. Upper hoist rigging assembly 5000 has a rigid connection bar 5010 extending between a pair of upper hoist links 5002. Each upper hoist link 5002 has lower clevis arms 5002A adapted to receive and secure an end of rigid connection bar 5010 and a link of an upper hoist chain 5003A by way of retainer pin 5030.

Similar to the double dump block applications previously discussed, by providing an upper hoist rigging assembly that has an upper hoist link with clevis arms adapted to secure both the rigid connection bar and an operative attachment to a respective upper hoist chain, the upper hoist rigging assembly of the invention has a lesser weight than prior art assemblies in view of the fact that less link members are required in the assembly. This reduced weight provides for productivity advantages over prior art assemblies as a greater proportion of the dragline's output capability is devoted to moving payload in the dragline bucket rather than in the hoist rigging assembly. The invention also has positive benefits to machine energy reduction due to more efficient and effective bucket handling.

Throughout the specification the aim has been to describe the invention without limiting the invention to any one embodiment or specific collection of features. Persons skilled in the relevant art may realize variations from the specific embodiments that will nonetheless fall within the scope of the invention.

It will be appreciated that various other changes and modifications may be made to the embodiment described without departing from the spirit and scope of the invention. 

1. A rigging assembly for a dragline excavator, the rigging assembly comprising: a first upper hoist link; a second upper hoist link; and an equalization member extending between the first upper hoist link and the second upper hoist link; wherein, the equalization member is formed from a flexible material.
 2. The rigging assembly of claim 1, wherein the equalization member is rotatably secured at an end thereof to the first upper hoist link and is rotatably secured at an opposing end thereof to the second upper hoist link.
 3. The rigging assembly of claim 1, wherein the equalization member is rotatably secured at either end thereof to a clevis arm of a respective upper hoist link.
 4. The rigging assembly of claim 1, wherein the equalization member is rotatably secured at either end thereof to a clevis arm of a respective upper hoist link by way of a pin.
 5. The rigging assembly of claim 3, wherein a link of an upper hoist chain is secured to the clevis arm of each of the upper hoist links.
 6. The rigging assembly of claim 1, wherein the equalization member is of a unitary construction.
 7. The rigging assembly of claim 1, wherein the equalization member has a shaft and a clevis arm located at opposing ends of the shaft.
 8. The rigging assembly of claim 1, wherein the equalization member is formed from linked chain.
 9. A rigging assembly for a dragline excavator, the rigging assembly comprising: a first upper hoist link; a second upper hoist link; an equalization member extending between the first upper hoist link and the second upper hoist link, the equalization member secured at an end thereof to the first upper hoist link by way of a retainer and secured at an opposed end thereof to the second upper hoist link by way of a retainer; an upper hoist chain secured to the first upper hoist link by way of the respective retainer; a further upper hoist chain secured to the second upper hoist link by way of the retainer. 